1. Technical Field
Example embodiments of the present invention relate in general to a local mobility anchor (LMA), a proxy router, and a management method for supporting network mobility (NEMO) in a proxy mobile IPv6 (PMIPv6) network, and more specifically, to devices and methods for supporting NEMO with only a PMIPv6 protocol for a mobile node in which a mobile IP function is not implemented.
2. Related Art
NEMO management techniques are next-generation mobility management technologies for effectively managing mobility of a number of mobile nodes having the same mobility pattern, and overcoming limitations in wireless coverage of a mobile node such as a Wi-Fi device by interworking with WiMAX or HSPDA access technology in an external interface, and Wi-Fi access technology in an internal interface. In an existing NEMO management method, a mobile IPv6 function is mounted in a mobile router (MR) and locations of mobile terminals located in a mobile network are managed. Here, mobile IPv6 is a node-based mobility support protocol.
However, the mobile IPv6 has a problem of handover performance due to an operation in which a host senses movement of a terminal, updates a location of the terminal, and re-generates an IP address according to a handover. Thus, PMIPv6, which is a network-based mobility management technique for providing a function of sensing the mobility of a node and updating the location of the node in a network, has been proposed.
In PMIPv6, a network performs mobility sensing requested for a mobile node. Resetting of an IP address is unnecessary within the same PMIPv6 domain. Thus, high-speed mobility management is achieved only by mounting an IPv6 protocol inside the mobile node. To provide an NEMO function based on merits of the PMIPv6 protocol, a procedural method supportable with a PMIPv6 network without a mobile IP protocol in an existing MR, and an effective handover method according to movement of a mobile network, are required.
FIG. 1 is a flow diagram showing a mobility management procedure according to a relay-based NEMO (rNEMO) management technique proposed in the related art.
Referring to FIG. 1, in the rNEMO management technique, NEMO can be supported without correcting a basic procedure provided in PMIPv6, by causing a relay node to be responsible for only relaying a signal and data through signal amplification between a mobile node and a mobile access gateway (MAG), instead of an existing MR. A process of adding and removing a tunnel header is removed in terms of packet delivery, so that unnecessary detour traffic is reduced.
However, when a mobile network including many mobile nodes moves to another MAG, all mobile nodes included in the mobile network should be connected to a new MAG. In this case, there is a disadvantage in that signaling for an existing mobility management/control procedure of individual mobile nodes should be generated, and location update is not cost-effective in consideration of a number of terminals within the mobile network.
Next, FIG. 2 is a flow diagram showing a mobility management procedure in NEMO-enabled PMIPv6 (N-PMIPv6), which is another NEMO management technique proposed in the related art.
Referring to FIG. 2, a moving MAG (mMAG) responsible for a MAG function in an existing MR is provided in N-PMIPv6. An LMA provides a location management function using the mMAG for mobile nodes within a mobile network. There is an advantage in that only addition of management information items for the existing MAG and LMA through the management of mobile network terminals using the mMAG is required, and locations of existing mobile nodes located within the mobile network are simultaneously updated only through an mMAG-based handover procedure during a network handover.
However, since the existing MAG does not know information of mobile network terminals, a tunnel header in which a destination IP address is delivered to the mMAG is delivered separately from a PMIPv6 tunnel header to be delivered from the LMA to the MAG in the case of a packet addressed to the mobile network. Thereafter, the MAG re-delivers the packet to the mMAG after removing one tunnel header, so that packet delivery overhead occurs in wired/wireless communication. In view of limited wireless network resources, excessive wired/wireless resources may be wasted in the existing N-PMIPv6 according to a number of mobile network terminals and a data transmission rate.
Accordingly, a new NEMO management technique is necessary which improves efficiency in terms of handover signaling as compared to rNEMO, and is cost-effective in terms of packet delivery as compared to that of N-PMIPv6.